Stirring Effects on Properties of Al Goethite Formed from Ferrihydrite

U. Schwertmann and H. Stanjek
Lehrstuhl für Bodenkunde, Technische Universität München, D-85350 Freising-Weihenstephan, Germany

Abstract: Minerals in surface environments form in both turbulent and non-turbulent systems. This study compares the properties of Al goethite formed from ferrihydrite at 60 °C in 0.3 M KOH with and without mechanical stirring. Compared to the static system, stirring increased crystal order and needle thickness, decreased unit cell edge length a, but not b and c, reduced the separation between the 2 OH-bending vibrations, increased Al substitution and promoted hematite formation.

Key Words: Al Goethite • Crystallinity • Hematite • Stirring • Unit Cell Parameters

Clays and Clay Minerals; June 1998 v. 46; no. 3; p. 317-321; DOI: 10.1346/CCMN.1998.0460310
© 1998, The Clay Minerals Society
Clay Minerals Society (www.clays.org)